Note On Intermittents

Manipulate circuit No. 472 wiring, IAT sensor and PCM connector while observing PCM parameter PD05. If failure is induced, manifold air temperature will jump from its normal value to shorted reading of 142-151°C. If wiring and connectors are okay, substitute a known good sensor, and retest.

Fig 1: PCM Code P037 Schematic - Shorted IAT Sensor Signal

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code P037 Flow Chart - Shorted IAT Sensor Signal

Courtesy of GENERAL MOTORS CORP.